not produced or when the receptors on the cells’ surfaces that should detect it are absent or defective.
Conversely, tumours of the pituitary may secrete excess growth hormone, and if this happens in childhood prior to fusion of the epiphyseal plates, then gigantism results. Although these tumours are extremely rare in childhood, they have produced two extremely well-known actors, including Richard Kiel (the infamous ‘Jaws’ villain from two James Bond movies) and Andre the Giant, a wrestler and actor from The Princess Bride.
As well as being giants over 7 ft (213 cm) tall, both of these stars exhibited the other effects of excess growth hormone secretion, a condition called acromegaly. If growth hormone secretion occurs after the long bones have fused, then you can’t grow any taller, but bones and other tissues continue to grow. The brow ridge and jaw thicken, the tongue and hands become vast and thick, and the voice deepens. In athletes using growth hormone as an illegal performance-enhancing drug, jaw changes often necessitate orthodontic braces to realign teeth – a subtle tell-tale sign for doping.
It’s a beautiful, complex cascade that we have been able to understand in greater and greater detail through the revolution in molecular biology and genetics over the last 50 years, but one particularly strange thing about our growth through childhood and adolescence has remained a mystery. Unlike any another primate, we have a very odd pattern of growth through to adulthood. As we’ve already seen in this chapter, the first six months of life witness the most rapid period of growth, but then this slows dramatically through the next 10 years – a time we humans call childhood. Unlike any of our nearest relatives, including chimpanzees and bonobos, we grow at a fraction of the maximal rate through this period. It’s as if the race to adulthood is on hold, until suddenly we burst into activity again around the age of 10 as we experience the growth spurt of puberty. The mystery is why. Why do we all follow this oddly stunted pattern of growth? In the last few years an intriguing hypothesis has emerged to explain the biological oddity we call childhood.
GOOD THINGS COME TO THOSE WHO GROW
In June 1765 Daines Barrington, the British lawyer, naturalist and distinguished fellow of the Royal Society, made his way the one mile from his home in King’s Bench Walk in the heart of legal London, to a rather less respectable address on the east side of Soho. The reason for his journey into this more unsavoury area of London was to visit the temporary occupants of 21 Frith Street – an Austrian man named Leopold and his two children 14-year-old Nanneri and 8-year-old Wolfgang.
Under his arm Barrington carried a clutch of documents and papers, but most importantly a newly composed music manuscript written in a ‘challenging, contemporary Italian style’. The purpose of bringing the manuscript was to place it in front of the young boy Wolfgang so that Barrington could check for himself whether the rumours that had spread across London regarding this boy’s precocious musical talent were really true. The boy was, of course, Wolfgang Amadeus Mozart and Barrington’s test would be an easy trial for him to pass. Just by sight, the young Mozart played the piece effortlessly and perfectly, at the very first time of trying. ‘The score was no sooner put upon his desk than he began to play the symphony in a most masterly manner, as well as in the time and style which corresponded with the intention of the composer,’ he wrote.
Barrington went on to further test the abilities of the 8-year-old boy, challenging him to improvise a song of ‘love and a song of rage’. Writing in a now famous letter to the Philosophical Transactions of the Royal Society some years later, Barrington described how Mozart’s
astonishing readiness, did not arise merely from great practice; he had a thorough knowledge of the fundamental principles of composition … and his transitions from one key to another were excessively natural and judicious.
‘EVEN TODAY, AFTER A CENTURY OR SO OF SCIENTIFIC STUDY OF CHILD DEVELOPMENT, PRECOCIOUS TALENT REMAINS A MYSTERY. WE ARE STILL AS CURIOUS ABOUT TALENT NOW AS PEOPLE WERE IN THE EIGHTEENTH CENTURY.’
PROFESSOR UTA FRITH
Barrington’s visit, tests and subsequent publication of his observations are widely regarded as one of the first examples of Behavioural Science. As Professor Uta Frith, a current FRS and one of Britain’s most distinguished cognitive scientists, wrote some 250 years later, ‘Naturally, the methods of observation he used are rather crude to our modern eyes, but, the crucial point is that he gives concrete examples of behaviour and not just opinions.’
It did not just take Barrington to prove that Mozart was undoubtedly a child genius. The historical records are full of details of his precocious talent, from his first compositions as a 4-year-old, to his first symphony, composed during that extended stay in London. This was a childhood that was truly full of extraordinary achievement, a unique talent that was maturing before the eyes and ears of the world. As Frith went on to conclude, ‘Even today, after a century or so of scientific study of child development, precocious talent remains a mystery. We are still as curious about talent now as people were in the eighteenth century.’
Achievement and emerging talent however, is not something that is in short supply with children of 4, 5, or 6 years of age. This is the moment that many of us sit our children down at the piano for the first time, sign them up for the local football team or send them off to ballet class as well as seeing them grasp the fundamentals of reading, writing and arithmetic skills that they will carry throughout their lives.
Subconsciously or not, we are aware that this is a precious time, a moment when children are more than just sponges; they are receptive to developing new skills and abilities with an ease that will not be repeated at any other time in their lives.
The foundation of all of this new-found knowledge, skill and ability is of course the brain, and intriguingly we now think the brain power that goes into all of this intensive learning is intricately linked to that mysterious and odd pattern of growth we were puzzling on earlier in the chapter.
On a daily basis your brain demands a huge amount of the energy your body uses. Weighing around 1.4 kg, just 2 per cent of our total body weight, the average adult human brain consumes 20 per cent of our body’s energy expenditure (to be precise that is 20 per cent of the resting metabolic rate [RMR]). To put this massive power demand into some context, if your body needs 1,400 calories just to sit on the couch all day doing sod all (that’s what the RMR is), then your brain will be consuming 280 of those calories just to keep things ticking over, like deciding which channel to watch, or when to eat dinner. Put another way, it takes one Mars bar plus an extra bite for your brain to exist. No other organ in the body is so hungry for energy, but what is interesting is that the energy demands of the brain are far from constant throughout your life.
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